Call transfer let's you pass control of the call to another phone.
If your working in a group environment with a number of extra VOIP lines it's often useful to transfer the call to another member of the group.
While in a call, call transfer lets you place the call 'on hold', call another number, then connect the 'held' call to the called number.
Call transfer can be performed 'attended' (waiting for the third party to pick up before transfer) or 'blind' (transferring before the third party picks up).
* This feature needs phone support.
See you phone manual for details.